B2 Organisation Flashcards
Adaptations of alveoli for gas exchange?
-l’âge surface area to volume ratio
- thin walls
-good ventilation
-good blood supply
Label heart
-
Pathway of blood starting from lungs
-lungs to pulmonary vein to left atrium
- through bicuspid valve into left ventricle-ventricle contracts and pushes flood out of aorta to the body
-de oxygen blood from body enters through right atrium through vena cave
- through tricuspid valve into right ventricle
- through pu,monary artery to lungs
What is a tissue?
A group of cells of similar structure working together for a specific function
What is an organ?
Made from a group of tissues working tg to perform a function
What is an organ system?
A group of organs with related functions working together to perform body functions within the organism
Name 3 tissues in the stomach
Glandular- secretes enzymes and stomach acid
Muscle - allows contraction
Epithelial- lines the stomach
What is an enzyme?
Biological catalyst that speeds up reactions without being used up
Name and the function of each body part in the digestive system
Mouth: mechanical digestion to increase surface area of food
Salivary glands: secrete amylase to break down starch
Oesophagus: the tube that connects mouth to stomach, peristalsis occurs to push food down
Stomach: protease enzymes are secreted, hydrochloric acid provides a suitable pH for enzymes and destroys pathogens
Liver: bile is produced, neutralises stomach acid
Gall bladder: bile is stored here
Pancreas: amylase, protease and lipase are produced here before the small intestine
Small intestine: acidic acid is neutralised and enzymes complete chemical digestion, food and water are absorbed by villi
Large intestines: remaining water is absorbed, faeces formed here
Rectume and anus: egestion
What is metabolism?
The sum of all reactions in the body
Describe how an enzyme works?
The substrate bind to the active site
What is the effect of temperature on an enzyme?
The enzyme works fastest at the optimum temperature (37(body temp))
As temp increases ,rate increases and if it becomes too hot then the bonds in the amino acids break and the enzyme is denatured, as the shape of the active site changes
Effect of pH on enzymes?
The optimum pH for most enzymes is 7, but some have a lower optimum (like in the stomach acid)
Is the pH is too high or too low the binds of amino acids can break the proteins and change the active site, therefore denaturing
RP: investigating the effect of pH of the rate of reaction of amylase (tile drops) METHOD
1)Place drops of iodine in down on the tiles
2) label a test tube w the pH
3) add the starch solution to the amylase and add pH buffer solution
4) free 10 senids place one drop of the mixture on the iodine
5) wait another 10 seconds and add another drop to the nest drop of iodine
6) repeat until the iodine remains the same colour
How can the iodine tile RP be improved?
Control the temp w a water bath
Take reading at shorter time intervals
Which enzymes break down carbohydrates? Give an example in the body
Carbohydrase: converts carbs into simple sugars
E.g amylase = starch to glucose in saliva
What enzymes break down proteins? Give an example in the body
Proteases: converts proteins into amino acids
E.g : pepsin in the stomach
What enzymes break down lipids? Give an example in the body
Lipases : converts lipids into glycerol and fatty acids
E.g pancreas and small intestine
What is the food test for starch? What is the result?
Iodine: turns black /blue
What is the food test for protein? What is the result ?
Biuret test! Turns purple
What is the food test for lipids? What is the result?
Ethanol : turns cloudy
Sudan III: red layer
What is the role of bile?
An alkaline solution that neutralises hydrochloric acid from the stomach
It emulsifies large drops of fat into smaller ones
Describe the Benedict’s test for sugars
1) set up a water bath with a Bunsen burner
2) add the food sample in a test tube and put it in the water bath
3) add a few drops of Benedict’s solution
4) wait 5 minutes and note down colour changes
Describe the iodine test for starch
Add the food sample to a tube
Add a few drops of iodine
Note down colour change
Describe the emulsion test for lipids
Add the food sample to a tube
Add a few drops of water and ethanol
Shake the solution gently and note own colour change
Describe the biuret test for protein
Add the food sample to a tube
Add a few drops of biuret
Shake gently, not down colour changes
Where are the coronary arteries?
On the outside of the heart, they provide blood and nutrients to heart cells
What is the diaphragm?
Sheet of tissue at the bottom of the throat
What are the function of the ribs?
Protect the lungs and heart
What is the intercostal muscle?
Muscle in between ribs
Where is the trachea?
The windpipe that connects the mouth and nose to the lungs
Where are epithelial cells?
In the trachea
Where are the bronchi?
Large tubes that connect the trachea to the lungs
Where are the bronchioles?
Smaller tubes that connect to the alveoli
Why is the wall of the left ventricle thicker?
It need to pump blood around the whole body at high pressure
What does the septum of the heart prevent?
Stops two sides from mixing
What do the pacemaker cells do?
In the heart (right atrium), send out impulses to control heart rate
What are artificial pacemakers?
Electrical devices that deliver an electric current to help it contract regularly
Describe an artery
Small lumen
Thick walls
To withstand high blood pressure and small lumen to maintain pressure
Describe a vein
Thin wall, large lumen, valves
No backflow of blood, high volume low pressure
Describe a capillary
One cell thick, easier for diffusion, narrow lumen, delivers o2
What is that calculus action for rate of blood flow?
Volume of blood / minutes
What is the composition of blood?
55 plasma
45 red blood cells WBCs platelets
What is the function of a red blood cell?
Transport oxygen
What are the adaptations of a red blood cell?
Bi concave shape ( surface area to volume ratio for diffusion)
No nucleus (more room for haemoglobin)
Haemoglobin (binds to oxygen)
What is the function of a WBC
Fights pathogens and disease
What are adaptations of WBCs
Lymphocytes have a large nucleus (produce antitoxins and antibodies quick)
Phagocytes autonomous
What is the function of a platelet
To clot wounds
What are the features of a platelet?
No nucleus
What is the function of the plasma
Helps recovery from injury, distributes nutrients, removal of waste, prevents infection
What is coronary heart disease?
A non communicable disease where the inner lining of the coronary arteries becomes blocked with a plaque like substance made of cholesterol called atherosclerosis
What are some causes of CHD
Smoking (damages artery walls)
High blood pressure (increased workload )
High cholesterol ( plaque is made of cholesterol)
Lack of exercise
Diabetes
Obesity
What are some solutions to CHD?
Stents, statins, bypass surgery, heart transplant, artificial heart
What is a stent and what are he disadvantages and advantages of using it
Small mesh tubes inserted in the arteries,
✅keeps the arteries open for better flow
Recovery time is quick
Long lasting
❌risk of blood clots (thrombosis)
Heart attack can happen during surgery
Infection
What is a statin and what are he disadvantages and advantages of using it
Drugs that decrease cholesterol by blocking an enzyme
✅reduced risk of CHD and stroke
Long term
Increases good cholesterol
❌ inconvenience
Side effects
May take time to have an effect
What is a heart transplant and what are he disadvantages and advantages of using it
Replacement of heart with a donor
✅saves lives
❌waiting list
Organ rejection
Lifelong medication
What is bypass surgery and what are he disadvantages and advantages of using it
Creating a new pthaway for the blood
✅ long term
❌major surgery
Long recovery
What is an artificial heart and what are the disadvantages and advantages of using it
✅shorter waiting list
Less chance of rejection
❌ not as effective
Uncomfortable
Blood clots
Infection
What are the solutions to a faulty heart valve?
Biological valve replacement ( pigs or cattle
Mechanical valve replacement (man made)
What the advantages and disadvantages of a biological heart valve?
✅effective
❌only lasts 12 years
What the advantages and disadvantages of a mechanical heart valve?
Lasts longs !
Constant medication needed to stop clotting
What is a benign tumour?
Growth of cells are in one place
Non cancerous
Doesn’t invade other tissues
Can cause pressure to an organ
What is a malignant tumour
Grows and spreads to other tissues
Cancerous
Tumour can split into blood stream
Can travel and stay in other organs
Cancerous cells divide more rapidly
What are the lifestyle risks that cause cancer
Smoking
Obesity
UV light
Viral infection
What is the epidermal tissue in a plant and what is its function?
Covers the whole plant (waxy cuticle)
Helps reduce water loss
What is the palisade mesophyll? What is its function
Tissue found under the epidermal tissue, has lots of chloroplasts, exposed to sun
Site of photosynthesis
What is the spongy mesophyll? What is the function?
Under the palisade mesophyll, lots of air space, allows gases to diffuse
What is translocation in a plant?
Movement of food substances made in the leaves up or down the phloem
What is transpiration in plants?
Loss of water vapour through leaves and stems of the plant
What is the function and adaptation of xylem and phloem cells
What are guard cells?
Kidney shaped cels that open and close the stomata
They are light sensitive and allows gas exchange
What is the structure of a protein?
Chains of amino acid molecules
What is the structure of starch?
Chains of glucose molecules
What is the strut tire of lipids?
Glycerol w three chains of fatty acids
What does bile do to lipids?
Emulsifies them, breaks the large molecules into smaller molecules, increasing the surface area of the lipid molecules
